The colibri_ohci_init function performs a register access through
the io_p2v() macro, which requires the IOMEM macro to be defined.

By explicitly including the asm/io.h header file that contains
this macro, we avoid the build error:

arch/arm/mach-pxa/colibri-evalboard.c: In function 'colibri_ohci_init':
arch/arm/mach-pxa/colibri-evalboard.c:68:2: error: implicit declaration of function 'IOMEM' [-Werror=implicit-function-declaration]
  UP2OCR = UP2OCR_HXS | UP2OCR_HXOE | UP2OCR_DPPDE | UP2OCR_DMPDE;
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Haojian Zhuang <haojian.zhuang@gmail.com>
Cc: Daniel Mack <zonque@gmail.com>

The SAAR and TAVOREVB machines try to call functions from
the PXAFB frame buffer driver from their platform code,
which only works if that driver is built-in.

This patch ensures that both the generic frame buffer
code and the specific pxafb driver are always enabled
when we build a kernel for one of the two boards.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Haojian Zhuang <haojian.zhuang@gmail.com>
Cc: Daniel Mack <zonque@gmail.com>

We normally don't hard-enable Kconfig options just because
a board contains a specific piece of hardware. In this case,
selecting SMC91X causes a build error, if we don't also enable
basic network device driver support.

Since the platform has no direct dependency on this driver
at link time, we can just remove the 'select' statement.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Haojian Zhuang <haojian.zhuang@gmail.com>
Cc: Daniel Mack <zonque@gmail.com>

The D-Link DNS-323 machine tries to unconditionally select CONFIG_PHYLIB,
but that has other dependencies that might not necessarily be enabled,
causing random build errors.

To work around this, this patch removes the 'select' statement and
instead uses a compile-time check to skip the phy_register_fixup_for_uid()
call if PHYLIB is not available in the kernel.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>

The definition for SIGBUS may not be visible without including
linux/signal.h, as I found during randconfig testing.

Adding an explicit include is certainly the right thing to do.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Acked-by: Gregory Clement <gregory.clement@free-electrons.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>

The code for h2 and osk implicitly assumes that the tps65010
driver is built-in, in order to perform the initial regulator
setup.

This is fine for most real uses, but it does get into the way
of build testing with 'make randconfig', since we don't want
platforms to implicitly select device drivers and subsystems
such as I2C.

This patch by contrast changes the board files to not call
into the tps65010 driver when that is not built-in, allowing
us to build all configurations including some that will not
work properly on this hardware.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Tony Lindgren <tony@atomide.com>

If CONFIG_OMAP_32K_TIMER isn't enabled, we will
try to use enable_dyn_sleep which wasn't defined
anywhere.

In order to fix the problem, we always define
enable_dyn_sleep as 0 when !CONFIG_OMAP_32K_TIMER.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

The msm_sdcc MMC driver and the msm_serial_hs uart driver both
use the pre-dmaengine interfaces provided by the MSM platform.

Since these drivers can be loadable modules, we should export
the functions used in the drivers.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David Brown <davidb@codeaurora.org>
Cc: Daniel Walker <dwalker@fifo99.com>
Cc: Bryan Huntsman <bryanh@codeaurora.org>

MSM7X00A has an open-coded version of debug_ll_io_init so it
can use MT_DEVICE_NONSHARED as required by the platform.

However, this fails to build on no-MMU kernels because the
debug_ll_addr function is not available. Since the iotable_init
function doesn't actually do anyting in this configuration,
we can simply get away by enclosing the broken function call
in an #ifdef, which seems to be the least ugly workaround.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David Brown <davidb@codeaurora.org>
Cc: Daniel Walker <dwalker@fifo99.com>
Cc: Bryan Huntsman <bryanh@codeaurora.org>

After the restructuring of the module.h and init.h headers,
we now need to include this explicitly here.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David Brown <davidb@codeaurora.org>
Cc: Daniel Walker <dwalker@fifo99.com>
Cc: Bryan Huntsman <bryanh@codeaurora.org>

This symbol is used by the lpc_eth driver, which may
be a loadable module.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Roland Stigge <stigge@antcom.de>

The 'og' machine tries to always initialized the PCI code, but that
may be disabled in Kconfig, leading to a build error.

This patch changes the code to use the same Kconfig symbol to decide
about calling the ks8695_init_pci function at build time that we
use to decide about building the ks8695 PCI support.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Greg Ungerer <gerg@uclinux.org>

Commit 098e30f6 "ARM: ixp4xx: stop broadcasting the custom GPIO API"
changed the internal gpio code of ixp4xx to be accessible only from
common.c, but unfortunately that broke the Goramo MultiLink code, which
uses this API.

This tries to restore the previous state without exposing the
API globally again. A better solution might be needed.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Krzysztof Halasa <khc@pm.waw.pl>
Cc: Imre Kaloz <kaloz@openwrt.org>

When using CONFIG_IXP4XX_INDIRECT_PCI, we run into a recursive
header file dependency between mach/io.h and asm/pci.h, resulting
in a build failure:

mach-ixp4xx/include/mach/io.h: In function 'is_pci_memory':
mach-ixp4xx/include/mach/io.h:53:18: error: 'PCIBIOS_MIN_MEM' undeclared (first use in this function)
  return (addr >= PCIBIOS_MIN_MEM) && (addr <= 0x4FFFFFFF);
                  ^
mach-ixp4xx/include/mach/io.h:53:18: note: each undeclared identifier is reported only once for each function it appears in

We can work around this by referencing the pcibios_min_mem variable
directly through an extern declaration, rather than using the macro.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Imre Kaloz <kaloz@openwrt.org>
Cc: Krzysztof Halasa <khc@pm.waw.pl>

The omixp board code unconditionally defines a gpio-led
device, but for some reason includes the header file
for this only if CONFIG_LEDS_CLASS is enabled, causing
a build error otherwise.

Removing the #ifdef fixes the build error with no downsides
whatsoever.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Imre Kaloz <kaloz@openwrt.org>
Cc: Krzysztof Halasa <khc@pm.waw.pl>

The hisi SMP code always uses the hi3xxx_set_cpu() function
defined in the hotplug.c file, so we cannot build without
this when CONFIG_SMP is enabled. This patch slightly restructures
the code so we always build the parts of hotplug.c that we need
but just leave out the CPU disable logic if CONFIG_HOTPLUG_CPU
is turned off.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>

ep93xx_chip_revision is used by the pata_ep93xx driver,
which can be a loadable module. Exporting the symbol
avoids a link error in this case.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ryan Mallon <rmallon@gmail.com>

The efm32 platform does not provide a zreladdr-y line its Makefile.boot,
so we always have to use CONFIG_AUTO_ZRELADDR in order to successfully
build and link a zImage.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Uwe Kleine-König <kernel@pengutronix.de>

The DAVINCI_DA850_EVM board uses an unusual method to
enable the GPIO_PCA953X and KEYBOARD_GPIO_POLLED symbols,
which leads to the dependencies on these symbols being
ignored. As GPIO_PCA953X actually requires I2C, that
can lead to build failures when I2C is disabled.

This patch removes the duplicate symbol definitions
and instead enables them from the davinci_all_defconfig
file.

A different question whether we actually want to automatically
enable them at all or rather put them into defconfig,
but that should be a separate patch.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Sekhar Nori <nsekhar@ti.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Cc: davinci-linux-open-source@linux.davincidsp.com

We cannot call phy_register_fixup_for_uid() if CONFIG_PHYLIB
is not built into the kernel, and we should not enforce that
to be built into vmlinux either, because one might want to
disable the entire network stack.

This change uses a compile-time condition on CONFIG_PHYLIB
to remove the call in the cases where it cannot work.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Sekhar Nori <nsekhar@ti.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Cc: davinci-linux-open-source@linux.davincidsp.com

It makes no sense for sama5 support to be enabled if we don't
also enable USE_OF. Making this automatic in Kconfig avoids
a possible randconfig conflict between the old and new clock
support code.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>

If CONFIG_PATA_AT91 is disabled, the code in at91_add_device_cf
is turned into invalid C statements due to the lack of an
expression before the 'else' clause.

This moves the first half of the condition inside of the #ifdef,
which seems to be what the author intended.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Andrew Victor <linux@maxim.org.za>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>

The pata_at91 driver uses interfaces defined in the sam9_smc
platform code. Since the pata driver can be a loadable module,
we have to export those symbols in order to link cleanly.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Andrew Victor <linux@maxim.org.za>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>

at91x40 has no support for device tree, but Kconfig allows
us to enable CONFIG_OF anyway, causing a link error in the
at91 reset controller initialization.

The easiest fix is to adapt the existing #ifdef to omit
the broken code on at91x40 where it is never called anyway.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Andrew Victor <linux@maxim.org.za>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>

at91x40 is different from all the other at91 machines, and it is
impossible to build a kernel that works on both this SoC and
any of the others, even though it is possible to build a noMMU
kernel for any at91 machine.

By turning at91x40 into a separate top-level option, we explicitly
forbid enabling invalid configurations that include mutually exclusive
machines.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Andrew Victor <linux@maxim.org.za>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>

Pull btrfs fixes from Chris Mason:
 "We have a small collection of fixes in my for-linus branch.

  The big thing that stands out is a revert of a new ioctl.  Users
  haven't shipped yet in btrfs-progs, and Dave Sterba found a better way
  to export the information"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: use right clone root offset for compressed extents
  btrfs: fix null pointer deference at btrfs_sysfs_add_one+0x105
  Btrfs: unset DCACHE_DISCONNECTED when mounting default subvol
  Btrfs: fix max_inline mount option
  Btrfs: fix a lockdep warning when cleaning up aborted transaction
  Revert "btrfs: add ioctl to export size of global metadata reservation"

Pull devicetree fixes from Rob Herring:
 "Fix booting on PPC boards.  Changes to of_match_node matching caused
  the serial port on some PPC boards to stop working.  Reverted the
  change and reimplement to split matching between new style compatible
  only matching and fallback to old matching algorithm"

* tag 'dt-fixes-for-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  of: search the best compatible match first in __of_match_node()
  Revert "OF: base: match each node compatible against all given matches first"

Currently, of_match_node compares each given match against all node's
compatible strings with of_device_is_compatible.

To achieve multiple compatible strings per node with ordering from
specific to generic, this requires given matches to be ordered from
specific to generic. For most of the drivers this is not true and also
an alphabetical ordering is more sane there.

Therefore, this patch introduces a function to match each of the node's
compatible strings against all given compatible matches without type and
name first, before checking the next compatible string. This implies
that node's compatibles are ordered from specific to generic while
given matches can be in any order. If we fail to find such a match
entry, then fall-back to the old method in order to keep compatibility.

Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Tested-by: Stephen Chivers <schivers@csc.com>
Signed-off-by: Rob Herring <robh@kernel.org>

Pull SCSI target fixes from Nicholas Bellinger:
 "Mostly minor fixes this time to v3.14-rc1 related changes.  Also
  included is one fix for a free after use regression in persistent
  reservations UNREGISTER logic that is CC'ed to >= v3.11.y stable"

* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  Target/sbc: Fix protection copy routine
  IB/srpt: replace strict_strtoul() with kstrtoul()
  target: Simplify command completion by removing CMD_T_FAILED flag
  iser-target: Fix leak on failure in isert_conn_create_fastreg_pool
  iscsi-target: Fix SNACK Type 1 + BegRun=0 handling
  target: Fix missing length check in spc_emulate_evpd_83()
  qla2xxx: Remove last vestiges of qla_tgt_cmd.cmd_list
  target: Fix 32-bit + CONFIG_LBDAF=n link error w/ sector_div
  target: Fix free-after-use regression in PR unregister

Pull i2c fixes from Wolfram Sang:
 "i2c has a bugfix and documentation improvements for you"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  Documentation: i2c: mention ACPI method for instantiating devices
  Documentation: i2c: describe devicetree method for instantiating devices
  i2c: mv64xxx: refactor message start to ensure proper initialization

Merge branches 'irq-urgent-for-linus' and 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq update from Thomas Gleixner:
 "Fix from the urgent branch: a trivial oneliner adding the missing
  Kconfig dependency curing build failures which have been discovered by
  several build robots.

  The update in the irq-core branch provides a new function in the
  irq/devres code, which is a prerequisite for driver developers to get
  rid of boilerplate code all over the place.

  Not a bugfix, but it has zero impact on the current kernel due to the
  lack of users.  It's simpler to provide the infrastructure to
  interested parties via your tree than fulfilling the wishlist of
  driver maintainers on which particular commit or tag this should be
  based on"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Add missing irq_to_desc export for CONFIG_SPARSE_IRQ=n

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Add devm_request_any_context_irq()

Pull timer fixes from Thomas Gleixner:
 "The following trilogy of patches brings you:

   - fix for a long standing math overflow issue with HZ < 60

   - an onliner fix for a corner case in the dreaded tick broadcast
     mechanism affecting a certain range of AMD machines which are
     infested with the infamous automagic C1E power control misfeature

   - a fix for one of the ARM platforms which allows the kernel to
     proceed and boot instead of stupidly panicing for no good reason.
     The patch is slightly larger than necessary, but it's less ugly
     than the alternative 5 liner"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tick: Clear broadcast pending bit when switching to oneshot
  clocksource: Kona: Print warning rather than panic
  time: Fix overflow when HZ is smaller than 60

Merge tag 'trace-fixes-v3.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull twi tracing fixes from Steven Rostedt:
 "Two urgent fixes in the tracing utility.

  The first is a fix for the way the ring buffer stores timestamps.
  After a restructure of the code was done, the ring buffer timestamp
  logic missed the fact that the first event on a sub buffer is to have
  a zero delta, as the full timestamp is stored on the sub buffer
  itself.  But because the delta was not cleared to zero, the timestamp
  for that event will be calculated as the real timestamp + the delta
  from the last timestamp.  This can skew the timestamps of the events
  and have them say they happened when they didn't really happen.
  That's bad.

  The second fix is for modifying the function graph caller site.  When
  the stop machine was removed from updating the function tracing code,
  it missed updating the function graph call site location.  It is still
  modified as if it is being done via stop machine.  But it's not.  This
  can lead to a GPF and kernel crash if the function graph call site
  happens to lie between cache lines and one CPU is executing it while
  another CPU is doing the update.  It would be a very hard condition to
  hit, but the result is severe enough to have it fixed ASAP"

* tag 'trace-fixes-v3.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace/x86: Use breakpoints for converting function graph caller
  ring-buffer: Fix first commit on sub-buffer having non-zero delta

Pull x86 EFI fixes from Peter Anvin:
 "A few more EFI-related fixes"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/efi: Check status field to validate BGRT header
  x86/efi: Fix 32-bit fallout

Pull ARM SoC fixes from Kevin Hilman:
 "A collection of ARM SoC fixes for v3.14-rc1.

  Mostly a collection of Kconfig, device tree data and compilation fixes
  along with fix to drivers/phy that fixes a boot regression on some
  Marvell mvebu platforms"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  dma: mv_xor: Silence a bunch of LPAE-related warnings
  ARM: ux500: disable msp2 device tree node
  ARM: zynq: Reserve not DMAable space in front of the kernel
  ARM: multi_v7_defconfig: Select CONFIG_SOC_DRA7XX
  ARM: imx6: Initialize low-power mode early again
  ARM: pxa: fix various compilation problems
  ARM: pxa: fix compilation problem on AM300EPD board
  ARM: at91: add Atmel's SAMA5D3 Xplained board
  spi/atmel: document clock properties
  mmc: atmel-mci: document clock properties
  ARM: at91: enable USB host on at91sam9n12ek board
  ARM: at91/dt: fix sama5d3 ohci hclk clock reference
  ARM: at91/dt: sam9263: fix compatibility string for the I2C
  ata: sata_mv: Fix probe failures with optional phys
  drivers: phy: Add support for optional phys
  drivers: phy: Make NULL a valid phy reference
  ARM: fix HAVE_ARM_TWD selection for OMAP and shmobile
  ARM: moxart: move DMA_OF selection to driver
  ARM: hisi: fix kconfig warning on HAVE_ARM_TWD

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Guenter Roeck <linux@roeck-us.net>

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

For non compressed extents, iterate_extent_inodes() gives us offsets
that take into account the data offset from the file extent items, while
for compressed extents it doesn't. Therefore we have to adjust them before
placing them in a send clone instruction. Not doing this adjustment leads to
the receiving end requesting for a wrong a file range to the clone ioctl,
which results in different file content from the one in the original send
root.

Issue reproducible with the following excerpt from the test I made for
xfstests:

  _scratch_mkfs
  _scratch_mount "-o compress-force=lzo"

  $XFS_IO_PROG -f -c "truncate 118811" $SCRATCH_MNT/foo
  $XFS_IO_PROG -c "pwrite -S 0x0d -b 39987 92267 39987" $SCRATCH_MNT/foo

  $BTRFS_UTIL_PROG subvolume snapshot -r $SCRATCH_MNT $SCRATCH_MNT/mysnap1

  $XFS_IO_PROG -c "pwrite -S 0x3e -b 80000 200000 80000" $SCRATCH_MNT/foo
  $BTRFS_UTIL_PROG filesystem sync $SCRATCH_MNT
  $XFS_IO_PROG -c "pwrite -S 0xdc -b 10000 250000 10000" $SCRATCH_MNT/foo
  $XFS_IO_PROG -c "pwrite -S 0xff -b 10000 300000 10000" $SCRATCH_MNT/foo

  # will be used for incremental send to be able to issue clone operations
  $BTRFS_UTIL_PROG subvolume snapshot -r $SCRATCH_MNT $SCRATCH_MNT/clones_snap

  $BTRFS_UTIL_PROG subvolume snapshot -r $SCRATCH_MNT $SCRATCH_MNT/mysnap2

  $FSSUM_PROG -A -f -w $tmp/1.fssum $SCRATCH_MNT/mysnap1
  $FSSUM_PROG -A -f -w $tmp/2.fssum -x $SCRATCH_MNT/mysnap2/mysnap1 \
      -x $SCRATCH_MNT/mysnap2/clones_snap $SCRATCH_MNT/mysnap2
  $FSSUM_PROG -A -f -w $tmp/clones.fssum $SCRATCH_MNT/clones_snap \
      -x $SCRATCH_MNT/clones_snap/mysnap1 -x $SCRATCH_MNT/clones_snap/mysnap2

  $BTRFS_UTIL_PROG send $SCRATCH_MNT/mysnap1 -f $tmp/1.snap
  $BTRFS_UTIL_PROG send $SCRATCH_MNT/clones_snap -f $tmp/clones.snap
  $BTRFS_UTIL_PROG send -p $SCRATCH_MNT/mysnap1 \
      -c $SCRATCH_MNT/clones_snap $SCRATCH_MNT/mysnap2 -f $tmp/2.snap

  _scratch_unmount
  _scratch_mkfs
  _scratch_mount

  $BTRFS_UTIL_PROG receive $SCRATCH_MNT -f $tmp/1.snap
  $FSSUM_PROG -r $tmp/1.fssum $SCRATCH_MNT/mysnap1 2>> $seqres.full

  $BTRFS_UTIL_PROG receive $SCRATCH_MNT -f $tmp/clones.snap
  $FSSUM_PROG -r $tmp/clones.fssum $SCRATCH_MNT/clones_snap 2>> $seqres.full

  $BTRFS_UTIL_PROG receive $SCRATCH_MNT -f $tmp/2.snap
  $FSSUM_PROG -r $tmp/2.fssum $SCRATCH_MNT/mysnap2 2>> $seqres.full
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>

bdev is null when disk has disappeared and mounted with
the degrade option

stack trace
---------
btrfs_sysfs_add_one+0x105/0x1c0 [btrfs]
open_ctree+0x15f3/0x1fe0 [btrfs]
btrfs_mount+0x5db/0x790 [btrfs]
? alloc_pages_current+0xa4/0x160
mount_fs+0x34/0x1b0
vfs_kern_mount+0x62/0xf0
do_mount+0x22e/0xa80
? __get_free_pages+0x9/0x40
? copy_mount_options+0x31/0x170
SyS_mount+0x7e/0xc0
system_call_fastpath+0x16/0x1b
---------

reproducer:
-------
mkfs.btrfs -draid1 -mraid1 /dev/sdc /dev/sdd
(detach a disk)
devmgt detach /dev/sdc [1]
mount -o degrade /dev/sdd /btrfs
-------

[1] github.com/anajain/devmgt.git
Signed-off-by: Anand Jain <Anand.Jain@oracle.com>
Tested-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>